UPDATE 3-Militants killed after audacious attack on Kabul airport

KABUL, July 17 (Reuters) - Militants armed with
rocket-propelled grenades attacked Kabul International Airport
in the Afghan capital on Thursday in one of the most audacious
assaults on the facility, used by both civilians and the
military, in a year.

The attack on the airport comes at a time of great
uncertainty for Afghanistan as votes from the second round of a
disputed presidential election are to be recounted. The poll is
meant to mark Afghanistan's first democratic transfer of power.

The attack lasted about four hours after four unidentified
militants armed with automatic rifles and rocket-propelled
grenades opened fire on the airport from the roof of a building
just to its north.

"Four terrorists were killed by police special forces. The
area is being cleared now, there are no casualties to our
forces," said Interior Ministry spokesman Sediq Sediqqi.

The airport is home to a major operational base for NATO-led
forces that have been fighting Taliban and other insurgents for
12 years and is bristling with soldiers and police, guard towers
and several lines of security checkpoints.

Militants fire rockets into the airport almost every week,
causing little damage, but frontal attacks on the heavily
guarded facility are rare and represent an ambitious target for
insurgents.

The attack was similar in tactics to last year's assault on
the airport, when seven Taliban insurgents including suicide
bombers attacked after taking up positions inside a partially
constructed building nearby.

There was no immediate claim of responsibility for the
latest attack.

A Kabul airport official told Reuters all flights had been
diverted to other cities. In such circumstances, passenger
planes are immediately diverted to other Afghan cities such as
Mazar-i-Sharif in the north or Herat in the west.

"Due to the closeness of the attack to the runway, Kabul
airport is now closed to all flights," the official said. Planes
could be heard circling above Kabul as the attack unfolded.

A Reuters witness near the scene earlier saw black smoke
billowing above the airport and heard several explosions. A car
had been set on fire not far from the scene.

On Tuesday, a car bomb detonated in a crowded market killed
43 people and wounded at least 74 in the eastern province of
Paktika, close to Afghanistan's porous border with Pakistan.
(Writing by Maria Golovnina; Editing by Paul Tait)